[pypy-dev] serialize and deserialize objects in Pypy

[Maciej Fijalkowski]

yes, you need a serializer protocol, like JSON (or protobuf or
anything). You generally need to express stuff in a way C can
understand and read it in python

On Fri, Aug 7, 2015 at 2:06 PM, Yicong Huang <hengha.mao at gmail.com> wrote:
> The problem is we might need to support several kinds of collection objects:
> list, dict, tuple.
> In addition, we might not know what is exact type of objects stored in the
> collections. A list might store int, string, double.
> So it might involve a lot of work to write the python wrapper.
> Do you have any good ideas?
>
> On Fri, Aug 7, 2015 at 7:46 PM, Maciej Fijalkowski <fijall at gmail.com> wrote:
>>
>> you really can't convert it to the C stuff like that. You need to do:
>>
>> foo = ffi.new("int[]", 13)
>> foo[0] = 12
>> foo[1] = 55
>>
>> etc.
>>
>> You can write nice python wrapper around those things too, if the data
>> is too bare bone.
>>
>> On Fri, Aug 7, 2015 at 1:09 PM, Yicong Huang <hengha.mao at gmail.com> wrote:
>> > Hi Maciej,
>> >
>> > Could you provide some details on how to use cffi buffers? (a simple
>> > demo
>> > code or documents)
>> > I tried the below code but it did not work.
>> >
>> > #python list
>> > x=[1,2,3,4]
>> > #intend to convert to c++ char*, but failed
>> > p=ffi.from_buffer(x)
>> > #intend to covert back to python list, but failed
>> > y=ffi.buffer(p)
>> >
>> > Thanks!
>> >
>> > -Ethan
>> >
>> > On Fri, Aug 7, 2015 at 6:24 PM, Maciej Fijalkowski <fijall at gmail.com>
>> > wrote:
>> >>
>> >> you can use cffi buffers (e.g. cffi char*) that you manipulate from
>> >> python using wrappers. They would behave (sort of) like python objects
>> >> and the wrapper code is really not a performance penalty in most cases
>> >>
>> >> On Fri, Aug 7, 2015 at 12:19 PM, Yicong Huang <hengha.mao at gmail.com>
>> >> wrote:
>> >> > Hi,
>> >> >
>> >> > Are there any good methods to serialize Pypy object to C++ char* and
>> >> > deserialize to Pypy object from  C++ char*?
>> >> >
>> >> > Our scenario like this:
>> >> > We have at least two C++ process running, and each process embeded
>> >> > Pypy
>> >> > to
>> >> > execute some functions.
>> >> > And we woule like to reuse Pypy object from one process to another
>> >> > process.
>> >> > For primitive objects, int/char/bool/double etc., we could use cffi
>> >> > to
>> >> > pass
>> >> > objects.
>> >> > Pypy object -> c++ process 1 -> c++ process 2 -> Pypy object
>> >> >
>> >> > But for complex objects, e.g. list/array/dict/tuple, are there any
>> >> > methods?
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > _______________________________________________
>> >> > pypy-dev mailing list
>> >> > pypy-dev at python.org
>> >> > https://mail.python.org/mailman/listinfo/pypy-dev
>> >> >
>> >
>> >
>
>